Many municipalities world wide discharge their waste-water effluent into local waterways such as rivers, brooks, and ponds. Typically, however, the flow of such waterways is inadequate to carry away the residual nutrients, namely phosphates and nitrates, resulting in eutrophication of those waterways. That is, weeds and algae grow uncontrollably, due to the excessive nutrients, resulting in depletion of available oxygen from the water. This results in killing the fish and amphibians which require the oxygen for survival and ultimately turns the rivers and ponds into swamps, devoid of marine life.
Removing the nutrients (phosphates and nitrates) and other contaminants (cadmium, cromium, copper, lead, mercury, nickel, zinc, etc.) to safe levels is cost prohibitive. Guidelines proposed by the Environmental Protection Agency (EPA) and State Departments of the Environment to reduce the phosphate limits even further exacerbate the need for a cost effective, efficient method for removing the contaminant which will meet or exceed the existing and proposed EPA guidelines.
Recent studies have estimated the cost of nearing, not even achieving, the proposed EPA requirement for even modest sized facilities at tens of millions of dollars. Moreover, even then the existing technology cannot meet the requirements necessary to reverse eutrophication. Other attempts to meet the EPA requirement required a substantially high chemical consumption, and still failed to meet the EPA requirement.
Alternatives to meeting the EPA requirements include natural treatments, constructed wetlands, biological treatments and even relocation of treatment facility effluent, all of which are cost prohibitive. Magnetic filtration and separation systems have been attempted in the past. These systems provided magnetic filtration after coagulation, magnetic seeding, and flocculation. They did not incorporate magnetic preconditioning or magnetic field treatment of any kind. The only use of magnetic fields was in the devices used for filtration of the seeded, e.g. magnetic, flocs from the fluid. They did not recognize the benefit to coagulation of the magnetic field conditioning. Thus, they required comparatively large amounts of chemical reagents. Moreover, they did not achieve sufficient contaminant removal. See U.S. Pat. No. 3,983,033, incorporated herein by this reference.
Magnetic treatment of water is disclosed in U.S. Pat. No. 438,579 where a magnetic field is applied to water flowing through pipes in a closed boiler system in order to prevent minerals from depositing on the inside of the pipes by keeping the minerals suspended and flowing; the minerals are not collected and removed from the system.
Several other processing systems have been implemented to prevent scaling of precipitated minerals by applying a magnetic field transverse to a fluid to precipitate the minerals from solution. However, descriptions of these treatment specifically state that "treatment does not eliminate the hardness salts but alters them physically". The precipitate is not collected. Prior art devices such as Moody, U.S. Pat. No. 3,228,878, do not collect the contaminant but merely change the physical character of scale producing mineral contaminants so that they flow through piping, heat exchangers, and the like, rather than adhere to the walls thus increasing pressure drop and decreasing heat exchange rate.